Amine-amide collectors for the treatment of potash ores

ABSTRACT

A collector composition especially suitable for the coarse flotation of sylvinite comprising: (A) at least about 90 percent by weight of a primary aliphatic amine of 16-18 carbon atoms, or water soluble salts thereof; and (B) about 0.5-10 percent by weight of a primary aliphatic amide of 10-20 carbon atoms.

United States Patent Inventors Appl. No.

Filed Patented Assignee Priority Robert Berthon Wittelsheim; Michel Mames, Ensisheim; Jean-Pierre Zimmerman. Cormeilles-en-Parisis, all of, France Dec. 28, 1967 Aug. 3, 1971 Mines De Potsse D'Absace S.A., France Jan. 6, 1967 France AMINE-AMIDE COLLECTORS FOR THE TREATMENT OF POTASH 011118 14 Claims, No Drawings Int. B031! {50]Fieldo1Search .Q

[56] References Cited UNITED STATES PATENTS 2,278,060 3/1942 Christmann et a1... 2,298,281 10/1942 Corley et a1. 2,329,149 9/ 1 943 Weiner 2,937,751 5/1960 Schoeld 3,009,575 11/1961 Keen et a1 Primary Examiner-Herbert B. Guynn Assistant E.taminerP. E. Willis Attorney-1. William Millen 20 carbon atoms.

AMINE-AMIDE COLLECTORS F OR TREATMENT I OF POTASI'IORES BACKGROUND OF THE INVENTION Upon further study of the specification and claims, other objects arid advantages of the present invention will become chloride (brine). Before being slurried into a pulp, the ore is comminuted-(dry or wet) to obtain a sufficient degree of liberation of the sylvite and halite crystals. It is then submitted to a desliming operation to remove at least the major part of the insoluble impurities which would otherwise interfere with the flotation. The pulp is then conditioned, either before its introduction into the flotation cells or right in the rougher cells themselves by adding the main flotation reagent-termed collector which adheres preferentially to the potassium chloride. Usually'auxiliary regulating agents are also added, such as a depressant which prevents or considerably reduces the detrimental effects of the insoluble impurities, and a frother which improves the dispersion of the air bubbles and facilitates the formation of froth enriched in the selectively coated particles of potassium chloride.

As the collector for sylvite contained in sylvinite ores, there has already been proposed aliphatic amines of 8 to 22 carbon atoms and/or their water-soluble salts, .in particular the acetates or hydrochlorides. In industrial practice, it is common to employ amines derivedfrom natural substances such as tallow, stearin, etc. which are composedprimarily of mixtures of primary amines having 16 and 18 carbon atoms.

These conventional reagents, however, do not always yield satisfactory results. In particular, when a coarse sylvite concentrate is desired, for example, one having particle. sizes larger than 0.6-0.8 mm. (28-20 mesh Tyler), these reagents often give poor to completely unsatisfactory results. To amelioratesuch situations, the addition of. modifying agents has been suggested in order to increase 'the extent of the hydrophobic coating on the sylvite particles previously coated with the amine collector, thereby increasing their floatability.

Among the prior art modifying agents with hydrophobic pro-v tions; petroleum oil fractions having predetermined characuse significantly increases the cost of the flotation process.-

Moreover, the modifying agents are not selective and will cause the flotation not only of the sylvite particles but also of the mixed crystals or middlings, it being nearly impossible to separate the latter during the subsequent'flotation steps,

SUMMARY OF THE INVENTION An object of thisinvention is to provide an improved collecting agent which will avoid disadvantages of prior art flotation systems.

Another object is to provide a flotation reagent system particularly suitable for the coarse flotation of sylvinite.

Further objects include improved flotation processes based on the collector composition of the invention.

apparent.

To attain these objects, thereis provided a collector com-' position comprising:

(A) at least 50 percent by weight of one or more primary aliphatic amines having 16-18 carbon atoms and/or the water-soluble-salts thereof; and 1 l (B) a sufficient amount of one or more primary aliphatic amides of 10-20 carbon atoms to increase the flotation separation efficiency of the amines.

The advantages of this collector composition are particularly outstanding when used for the flotation of sylvinite ores. Thus, the following detailed description is directed to a preferred embodiment of this invention. However, it is not intended that this invention be limited to such embodiment inasmuch as the collector composition of this invention is generally useful in the flotation of ores amenable to the use of amine collectors, for example, in the flotation of other potash ores such as langbeinite and a large variety of nonmetallic ores such as fluorspar, feldspar, mica and the like.

DETAILED DESCRIPTION OF TI-IEINVENTION According to the preferred embodiment, potassium chloride is floated from a sylvinite ore by using a collector agent consisting essentially of a major proportion of an aminated reagent selected from the group of primary aliphatic amines having 16-18 carbon atoms, their mixtures and water-soluble salts thereof, and a minor proportion of an amide selected from the group of primary aliphatic amides containing from IOto 20 carbon atoms in the molecule and mixtures thereof. This collector also gives excellent results without any addition of a hydrophobic modifying agent. In particular, by using this collector, a concentrate of sylvite having a large particle size, for example larger than 0.6-0.8 mm. (28-20-mesh), can be floated very efficiently.

The amides which can be used according to the invention are primary amides unsubstituted on the nitrogen atom, having as a general formula RCONl-i wherein R is a saturated or unsaturated-aliphatic radical. Such amides containing 10-20 carbon atoms in the molecule can be used either alone or in mixtures containing any proportion thereof. Preferably, there are used amides containing 12-18 carbon atoms, and in particular, the lauric, palmitic, stearic and oleic amides obtained from commercial fatty acids derived from natural substances. Laurie amide provides exceptionally good results, as will be seenfrom Example 4.

It has been observed that the amide(s) as hereinabove described increases the efficiency of the collector markedly. The synergism is so great between the components that even a very low proportion of amide in an amine collector increases its efficiency. For example, all other conditions being equal, it has been found that the addition of 1 percent by weight of an .amide or a mixture of amides to an amine collector can increase the yield of the flotation of the coarse particles by up to 50 percent.

In practice, it is preferred that the total amine-amide collector contain from about 0.5 to 10 percent by weight of amide. However, beyond about 5 percent by weight of amide, the improvements due to the increased quantity of amide are relatively small. Consequently, an economic balance is required to determine the optimum'amount for each individual system. Generally, however, a collecting agent containing from 1 to 5 percent amide and, preferably, 2 to 3 percent amide, is economically advantageous.

The use of an amine collector doped with an amide yields different advantages according to the type of flotation utilized. When standard flotation is employed to obtain a potassium chloride having a particle size not larger than 0.6-0.8 mm. (28-20 mesh), the use of the collector of this invention in the same quantity as (or in lower quantity than) conventional collectors yields tailings having a lower (or equal) residual potassium chloride content. It is therefore possible to selectthe desired alternative in any given beneficiation system.

The salutary effect of the amides is more dramatic when the amine-amide collector is used for the coarse or granular flotation of a potassium chloride of mostly above 0.8 mm. 1n this case, there is obtained an extraordinary increase in the flotation yield. (in this connection, it is well to realize that even a small increase in yield such as 1 percent is of substantial economic importance in this highly competitive field).

The new collector compositions can be prepared from the usual amine reagents containing essentially primary aliphatic amines having 16-18 carbon atoms or any mixture thereof. In order to obtain the very best results, there are preferably used amine collectors containing a-major proportion of primary saturated amines and a very low proportion of secondary or tertiary amines and unsaturated amines with respect to the total amine content. Thus, a particularly efficient collector composition can be prepared by adding the amide to an amine reagent containing more than 90 percent, and preferably more than 95 percent primary amines with respect to the total quantity of amines and having an iodine number lower than about 4.5, as measured by any conventional method such as, for ex ample, the modified Wijs method.

When the amines are used as water-soluble salts (e.g.

acetates or hydrochlorides), the amide is preferably added before the aminesare converted into their salts. By water-soluble it is to be understood that at least about 0.1 g. of the salt is soluble, per liter, in water at 20 C., fatty amine salts behaving in fact in aqueous solution as association colloids.

The amines and amides are made by conventional methods set forth in the literature e.g. by catalytic hydrogenation of the corresponding nitriles (for amines) or by action of ammonia on the corresponding fatty acids (for amides).

The amine-amide collectors can be used with the various conventional auxiliary reagents generally employed in flotation operations: depressants, such as starch, guar flour, proteins, cellulose derivatives, etc., frothers, such as pine oil, methylisobutylcarbinol and analogs thereof; pH regulators; flocculators; and/or dispersants.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the specification and claims in any way whatsoever.

EXAMPLE 1 A sylvinite ore containing 19 percent K,O, comminuted so that 95 percent of the particles have a size lower than 0.6 mm., was beneficiated on a laboratory scale. Eighty grams of a collector consisting of a stearylamine acetate containing 95 percent primary amine and having an iodine value of 4, was em ployed per 1000 kg. of dry ore without any auxiliary reagent.

A series of flotation tests were preformed with this collector to which were added various quantities of palmitic amide in percent by weight based on the total content of amine plus amide.

The results are as follows:

Palmitic amide taupe-.

EXAMPLE 2 Example 1 was repeated except that palmitic amide was There was used the same collector as in Example 1 but in a quantity equal to 50 g./t. (t.=1,000 kg.).for one series and g./t. for the other series of experiments. As auxiliary reagents, there was used 100 g. /t. potato starch and 100 g./t. pine oil.

The following results were obtained with the addition of various quantities of palmitic amide:

Amide Flotation yield 70 50 ./t. 100 g./t.

The flotation yield is thepercentage of KCl recovered in the concentrate, calculated with respect to the initial quantity of KCl in the ore.

EXAMPLE 4 Beneficiated on a laboratory scale was sylvinite ore containing 17.9 percent 0 and having the following particle size:

larger than 2.4 mm. (+8 mesh) 0.3% 2.4-1.7 mm.(8+ 10 mesh) 27.1% 1.7-1.2 mm. (10+14mesh) 51.3% 1.2-0.8 mm. (14+20 mesh) 18.7% lower than 0.8 mm. (-20 mesh) 2.6%

As the collector there was used a commercial stearylamine acetate (98.3 percent primary amine; iodine value 3) and 0 percent, 2 percent or 5 percent lauric amide. By employing 50 g./t. or 100 g./t. of the collector with 100 g./t. of potato starch and 100 g./t. of pine oil, the following results were obtained:

Reagent Flotation Yield k 50 g./t. 100 g./t.

stearylamine acetate 68.6 82.8 SA 2% lauric amide 84.8 90.3

SA 5% lauric amide 86.1

, EXAMPLES Example 4 was repeated except that lauric amide was replaced by oleic amide. The results were as follows:

Reagent Flotation yield '5 50 g-ll. I gJt.

SA 68.6 82.8 SA 2; oleic amide 7,8.4' 86.8 SA 5% oleic amide 84.9 89.8

The preceding examples can be repeated with similar success by substituting the generically and specifically described reactants and operating conditions of this invention for those used in the preceding examples. 1

From theforegoing description, one skilled in the art can easily ascertain the essential characteristics of this invention,

7 and without departing from the spirit and scope thereof, can

group consisting of at least one primary fatty amine of 'l 6--- 18 carbon atoms, at least one water-soluble salt thereof, and mixtures thereof; and

B. at least one primary fatty amide of l0-20 carbon atoms, said amide being present in a minor amount sufficient to increase the flotation efficiency of the amine reagent, said amount being about 0.5 10 percent of the composition.

2.-A collector composition as defined by claim 1 wherein the amount of amide is about 2 to 3 percent. 3. A collector composition as defined by claim 1 wherein theamount of amide is 1-5 percent.

4. A collector composition as defined by claim 1 wherein said amide is selected from the group consisting of lauric, palmitic, stearic, oleie, and mixtures thereof.

5. A collector composition as defined by claim 1, wherein said amine reagent exhibits an iodine number lower than 4.5.

6. In the beneficiation of sylvinite ores by froth-flotation, the improvement comprising using as a collector, the collector composition as defined by claim 1. I 1

7. In the beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim 2.

8. ln beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim 3.

9. ln the beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim 4.

' 10. In the beneficia tion of sylvinite ores by froth flotation, the improvement comprising usingas a collector, the collector composition as defined by claim 5.

11-. A process asdefined by claim 6 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.

-l2. A process as defined by claim 7 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.

1 13. A process as defined by claim 8 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.

14. A process as defined by claim 8 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,596.763 Dated August 3. 1971 n Robert Berthon Wittelsheirn et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Claims:

Claim 8, after "In" please insert ---the---;

Claim 14, line 1, "claim 8" should be --claim 9----.

elijfiw'l and sealed this 5th day of September LX172.

Atte st:

TQDJJAHD M.PLPJTJHEhgJM. ROBERT GOTTSUHALK Attestih'm iHi'ice-r' Commissioner of Patents JRM POJHQO [10-69] UscoMM-Dc 0 7mm 

1. A flotation collector composition consisting essentially of, on a weight basis: A. at least 90 percent of amine reagent selected from the group consisting of at least one primary fatty amine of 16-18 carbon atoms, at least one water-soluble salt thereof, and mixtures thereof; and B. at least one primary fatty amide of 10-20 carbon atoms, said amide being present in a minor amount sufficient to increase the flotation efficiency of the amine reagent, said amount being about 0.5-10 percent of the composition.
 2. A collector composition as defined by claim 1 wherein the amount of amide is about 2 to 3 percent.
 3. A collector composition as defined by claim 1 wherein the amount of amide is 1-5 percent.
 4. A collector composition as defined by claim 1 wherein said amide is selected from the group consisting of lauric, palmitic, stearic, oleic, and mixtures thereof.
 5. A collector composition as defined by claim 1, wherein said amine reagent exhibits an iodine number lower than 4.5.
 6. In the beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim
 1. 7. In the beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim
 2. 8. In beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim
 3. 9. In the beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim
 4. 10. In the beneficiation of sylvinite ores by froth flotation, the improvement comprising using as a collector, the collector composition as defined by claim
 5. 11. A process as defined by claim 6 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.
 12. A process as defined by claim 7 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.
 13. A process as defined by claim 8 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particle size of higher than 0.8 mm.
 14. A process as defined by claim 8 wherein said froth flotation is a coarse flotation separating particles of sylvite having a predominant particlE size of higher than 0.8 mm. 